Great hike, first 3 miles or so fairly flat then you start a gradual climb.  About 4 miles in there are two 60 yard up hill stretches that are the steepest sections I have ever done and you need to be very careful going up them, I couldn't imagine going down them.  Great clear cool day, you go through Juniper camp grounds before you take the 800 foot elevation summit trail.  People can drive to the summit so there can be a fair amount of people up there but still amazing views of the bay area on a clear day.  You come down the back side ridge with even more great views.  I did a 21 mile loop but shorter trails are available.